NumberResearch Membership · Data 09/20/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/20/2026

Full prefixes (NXX) Thousands-blocks (1,000-number pools)

The Code holder is who opened each NPA-NXX prefix — not necessarily who holds the numbers. A prefix is 10,000 numbers, but under pooling its ten 1,000-number blocks are handed out individually, often to different carriers; the code holder may hold only one block, or none. The Thousands-blocks column shows how the ten blocks are really split — click which blocks → to see who holds each 1,000-number block and its last-4-digit range. Assignments are initial assignments; the current serving carrier may differ due to portability.

Most active assignees, all time — NPA 302
MCIMETRO ACCESS TRANSMISSION SERVICES LLC 36
MCIMETRO ACCESS TRANSMISSION SERVICES LLC - DE 3
New assignments by month Sep 2026 Aug 2026 Jul 2026 Jun 2026 May 2026 Apr 2026 Mar 2026 Feb 2026 Jan 2026 Dec 2025 Nov 2025 Oct 2025
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Recent NPA-NXX prefix assignments
AssignedNPA-NXXThousands-blocks taken (last-4 opening)Code holderOCNRate centerState
2024-12-11 302-673 0–9 XXXall 10 · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 MILFORD DE
2022-08-05 302-618 0–9 XXXall 10 · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 NEW CASTLE DE
2018-12-06 302-485 0–9 XXXall 10 · 7 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WILMINGTON DE
2018-03-06 302-301 0–9 XXXwhole prefix which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 NEWARK DE
2017-11-03 302-291 0–9 XXXall 10 · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - DE 7220 LEWES DE
2017-05-10 302-274 0–9 XXXall 10 · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WILMINGTON DE
2015-03-17 302-516 0–9 XXXall 10 · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - DE 7220 WILMINGTON DE
2011-09-07 302-660 0–9 XXXall 10 · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - DE 7220 WILMINGTON DE
2010-09-28 302-585 0–9 XXXall 10 · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 HOCKESSIN DE
2010-09-27 302-400 0–9 XXXall 10 · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 NEW CASTLE DE
2010-09-27 302-499 0–9 XXXall 10 · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 DELAWARECY DE
2010-08-31 302-408 0–9 XXXall 10 · 6 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 HOLLY OAK DE
2010-08-31 302-414 0–9 XXXall 10 · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 NEW CASTLE DE
2010-08-31 302-597 0–9 XXXall 10 · 3 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 DELAWARECY DE
2010-08-30 302-583 0XXX1XXX2XXX3XXX5XXX6XXX7XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 DELAWARECY DE
2004-06-22 302-288 0–9 XXXwhole prefix which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WILMINGTON DE
2004-06-07 302-338 0–9 XXXwhole prefix which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 NEWARK DE
2004-06-07 302-340 0–9 XXXwhole prefix which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 DELAWARECY DE
2004-06-07 302-341 0–9 XXXwhole prefix which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 NEWARK DE
2004-06-07 302-361 0–9 XXXwhole prefix which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 HOCKESSIN DE
2004-06-07 302-370 0–9 XXXwhole prefix which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 NEW CASTLE DE
2004-06-07 302-371 0–9 XXXwhole prefix which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 HOLLY OAK DE
2004-06-07 302-372 0–9 XXXwhole prefix which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 HOCKESSIN DE
2004-06-07 302-374 0–9 XXXwhole prefix which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 HOLLY OAK DE
2004-06-07 302-380 0–9 XXXwhole prefix which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 DELAWARECY DE
2004-04-30 302-347 0–9 XXXwhole prefix which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 GEORGETOWN DE
2004-04-30 302-348 0–9 XXXwhole prefix which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 GEORGETOWN DE
— 302-258 3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 GEORGETOWN DE
— 302-261 2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 DELAWARECY DE
— 302-269 2XXX4XXX5XXX6XXX8XXX9XXX which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 DOVER DE
— 302-353 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WILMINGTON DE
— 302-385 2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 HOLLY OAK DE
— 302-397 1XXX3XXX4XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WILMINGTON DE
— 302-450 0–9 XXXall 10 · 7 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 DOVER DE
— 302-689 2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 NEW CASTLE DE
— 302-691 3XXX5XXX7XXX8XXX9XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WILMINGTON DE
— 302-729 2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 HOCKESSIN DE
— 302-861 2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 NEWARK DE
— 302-985 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 WILMINGTON DE

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/20/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.